Francis draper



Pattd March 20, 1844,

F. DRAPER.

' Lamp Cap.

'MIU

N. PETERS. PhmLMgnpMr, Washington. BC.

untreu sri/fires rgrnn'r formen.

FRANCIS DRAPER, Oli"` EAST CAMBRIDGE; MASSACHUSETTS.

y LAMP-CAP.

Specification of Letters Patent No. 3,500, dated March 20, 1844.

To CZZZ whom, may concern Be it known that I, FRANCIS Daarna, of EastCambridge, in the county of Middle-` sex and StateofMassachusetts,haveinvented a new and useful improvement in lamp-caps, for the purposeof preventing the oil that rises through the airtube or otherwise fromrunning over and down the exterior of the lamp, and that the followingdescription, taken in connection with the'accoinpanying drawings,hereinafter referred to, forms a full andexact specification ofvthesame, wherein I have 'set forth 'the nature and principles of my saidimprovement, by which my inventionmay` be distinguished from others fora similar purpose, together with such part as I claim and desire to havesecured to me by Letters Patent.

A recent device for accomplishing the re sult aforenamed, as the objector purpose of my improvement, has been `to form an independent cup aboutthe wick-tubes and connected to the same which c up is screwed to thecap of the lamp. The principal objection to this contrivance is, thatthe oil when it swells in the lamp will ooze out through the screw inthe same manner as it does in an ordinary lamp cap which is screwed intothe top of the fountain instead of being cemented to or around the same.Ther-e are other objections to this plan, such as its want ofsimplicity, &c., which will be apparent on an inspection of Figure l,which is a vertical section of such a cap, the., a fr being the cap andb the cup, the two being screwed together as above described at c, c.Between the cap i and cup a leather washer has sometimes been inserted7but it will be `perceived that when the leather becomes saturated, the`oil will be expressed and run down upon the lamp.

My improvement will etfectually Vobviate the aforedescribed evih (as itavoids having a screw in such place as will allow the oil to get to theoutside of the lamp,) and consists in extending the perimeter of the capupward around the wick tubes to a proper height toforni a deep cup, thesides or rim of the cup being bent or curved .in any proper manner toholdthe oil. The screw plate of thevwick tubes forms the bottom of thiscupfsaid plate being screwed` into the rim of the cap which extends downinto the fountain as will be explained in the sequel.

`Fig. 2, represents such an arrangement, said ligure being a verticalsection of my improved cap and of the wick tubes and Fig. 3 being anelevation of the same.

Z d is the cap which is formed according to my improved plan recentlypatented with a circular groove or channel e e, into which the top of aglass or other lamp is fitted or cemented; the exterior rim j f of saidgroove fitting on the outside of the top of the lamp, and the interiorrim g c/ being fitted to the inside of the same, or descending into thefountain of the lamp as herein above suggested. A proper female screw iscut on the inside of this latter rim into which the plate fr 7L of thewick tubes is screwed as shown at i a' in Fig. 2.

" rEhe cup Z Z is formed by extending the perimeter of the cap upward ashereinbefore described and as shown at 7c which forms the rim or sidesof the cup. This rim may be bent as shown in the drawing Fig. 2, or inany other proper way for the purpose of efiectually` holding the oil. Bysuch a conformation of the lamp cap as that above described as myimprovement it will be seen that whatever oil passes between the screwof the rim g g at that of the plate It 7L at z' z' must pass down theinside of said rim into the fountain. y

Having thus described my improvement inlamp caps I shall specify myclaim as follows.

I claim- Forming an oil cup about the wick tubes, and above the top ofthe plate of the same, by extending the perimeter or exterior rim f" fof the. cap upward as hereinbefore specied and for the purposehereinabove set forth, thereby superseding the use of screw in suchplace as will allow the oil `to get to the outside of the lamp.

In testimonythat'the foregoing is a true description of my saidinvention and iinprovement I have hereto set myV signature thisnineteenth day of February in the year eighteen hundred and forty four.FRANCIS DRAPER. lllitnesses:

` EZRA LINCOLN., J r., SAMUEL NEWTON.

